This study will continue to investigate the actions of the larynx involved in different phonation types, relating them to acoustic attributes of the sounds produced. In addition, the respiratory and other mechanisms providing power for speech sounds in different languages will be investigated. Voice qualities are hard to describe in objective terms, partly because observers often do not agree on what counts as an exemplar of a particular voice quality. However a wide range of languages differentiate words by means of the consistent use of "breathy" or "creaky" types of voice that occur in English only in the speech of those who have voice disorders. This research will correlate the physiological properties of these contrastive sounds with simultaneously obtained acoustic measures. The proposed research will continue development of new computer algorithms for quantifying differences of phonation type and breath stream dynamics, and compare the computed measures with the judgments of both speakers of different languages who use such contrasts for linguistic purposes and groups of trained listeners. It will also determine whether some speakers who use distinctive phonation types in their languages are clinically deviant. An underlying aim of the research is to elucidate what laryngeal and respiratory functions people control when they talk. Speech pathologists and laryngologists will benefit from these detailed studies of linguistically contrastive sounds. The data will also be important in studies of the full range of the capabilities of the normal human larynx and respiratory system.